Search PubMed⌕ Search

Biomedical subjects

K Steinbach

Publications and source records attributed to K Steinbach.

At least 73 records · Page 4Linked to original sources
PubMed1982

[New trends in cardiac pacing (author's transl)].

The introduction of new technologies has led to the development of pacemakers which restore the synchronized contraction of the atria and ventricles and suppress tachyarrhythmias. Programmability of amplitude, impulse duration, sensing function, refractory period, and hysteresis allow adaption of pacemaker function to the patients need.

Atrioventricular Node↗
PubMed1982

[Computer assisted long-term ECG analysis: method and clinical importance (author's transl)].

The basic principle of computer assisted analysis of Holter recordings is to store the whole ECG after data reduction and AD conversion in digitized form on random access medium like magnetic disks. In "Multipass Scanning" the linear segmentation techniques leads to highly reproducible ECG-data, which were analysed during multiple passes under continuous operator control. The field of clinical applications of such a highly sophisticated method reaches from supraventricular over ventricular to symptomatic arrhythmias. In combination with ECG-telefon-telemetry computer assisted LT-ECG analysis could be used in more than 75% of the patients successfully. The clinical expectations during routine could be fulfilled in more than 75%. Commonly a detailed numerical or graphical description of clinical relevant arrhythmias were necessary in the demand of the routine. So computer assisted LT-ECG analysis is not only a tool for research, but also valuable in the clinical routine.

Arrhythmia, Sinus↗
PubMed1981

[Computer-assisted long-term ECG analysis in patients with artificial trial pacemaker (AAI) (author's transl)].

Control of AAI-function is limited. To investigate the efficacy of AAI-stimulation, a computer-assisted analysis system for long-term ECG records was developed using "Multipass-Scanning I". 12 patients (5 females, 7 males, 33--78 years old with AAI) underwent Holter-monitoring for 24 hours continuously. THe ECGs of 5 among the collective with heart rate programmable AAI were recorded three times each with different AAI stimulation rates (50--80 b.p.m.). The number of AAI-induced heart beats in relation to the total number of QRS-complexes (AAI-QRS%) was 43 +/- 37% mean. AAI-QRS% during day showed a significantly lower distribution (35 +/- 38%, p less than 0.01) than during night (58 +/- 40%, p less than 0.001). Using an AAI-stimulation frequency of 50 b.p.m., only 9% of the heart beats were AAI-induced during day. Whereas AAI-QRS% increased to 72% during night in patients with AAI-stimulation frequency of 70 b.p.m. The interval between the PM-spike (S) and the following answer of the heart, i.e. SR-interval, demonstrated also a circadian behaviour: SR max occurred between 10 p.m. and 2 a.m. It was significantly prolonged to the SR min. (9--31%, m 20%, p less than 0.0001), which occurred between 9 a.m. and 4 p.m. So the presented computer-assisted long-term ECG analysis system for AAI-pacemakers is able to evaluate the efficacy of AAI with regard to different AAI-stimulation rates. The quantity of AAI-induced heart beats is dependent on patient's heart rate, its circadian behaviour and the stimulation rate of the AAI. The SR-interval also demonstrated a significantly circadian pattern, which can be related to the vagus-influenced PQ- and also AH-interval.

Adult↗
PubMed1981

[Quantitative evaluation of an antiarrhythmic therapy (disopyramide) in patients with frequent premature ventricular contractions (PVC) using a computer-assisted long-term ECG analysis system (author's transl)].

15 patients (pts.) - 12 males, 3 females - with frequent PVC (greater than 3%/16 hr during a qualifying period = LP) of different causes underwent after one-day placebo application (PL) drug treatment (disopyramide: loading dose 600 mg, 300 mg t.i.d.) over two days (D1, D2). The ambulatory continuously recorded long-term ECG was analysed using "Multipass-Scanning", a computer-supported analysis system for quantification of therapeutic success. The mean PVC rate of 17% prior treatment could be diminished in 87% of the pts. significantly. 5 pts. (group I) demonstrated a maximal PVC-reduction rate of more than 90 rel %. Among them in 2 pts. the PVC-rate did not exceed the 1%-level during D1 and D2 demonstrating an optimal therapeutic success. The max. PVC-reduction rate ranged between 80 and 90 rel % in 3 pts. (group II) and between 38 and 78 rel % in 5 pts. (group III). 2 pts. did not respond on DP. The mean DP-plasma level was higher in group-III pts. than in group-I or -II pts. in spite of a less therapeutic success. 7 pts. demonstrated a circadian behaviour of PVCs. Therefore the circadian variability increased. Also lower PVC rates under DP (D1, D2) led to an increase of spontaneous variability of PVCs. The maximal PVC depressant effect of DP appeared while the heart rate was 70 b.p.m. or higher. In conclusion, 87% of the pts. demonstrated a drug effect, but an effective antiarrhythmic therapy occurred only in 2 pts. (13%). A decrease of the frequency of rhythm disturbances led to a decrease of arrhythmia's variability and requires a prolongation of the ECG-recording time to eliminate the variabilities of arrhythmia occurred (spontaneous, circadian) and to avoid a mimicked therapeutic success.

Adolescent↗
PubMed1981

[Hypotension in Austria (author's transl)].

A representative group of the Austrian population was surveyed to gain informations about various aspects of the blood pressure problem. 22% of the persons surveyed (16-70 years) reported hypotension and 14% hypertension. Especially women very often (29%) consider their blood pressure rather low. 17% of the respondents consider hypotension "very dangerous", 47% "dangerous under certain conditions"; 30% prefer the statement "rather not dangerous". Women are less concerned about hypotension than men. Although hypotension very often is not recognized as a serious health problem this issue has implication on morbidity statistics and other aspects of public health, e. g. frequency of medical consultations, drug treatment, health economy. The population shows a high degree of awareness of this question of health.

Adolescent↗
PubMed1979

Studies on the toxicology of hexachlorobenzene. IV. Sulphur-containing metabolites.

After administration of hexachlorobenzene rats excrete sulphur-containing conjugates from which pentachlorothiophenol can be split off. In the present study we describe the identification of pentachlorothiophenol and pentachlorothioanisol in the livers of animals treated with hexachlorobenzene. In order to clarify the further fate of these two substances, we administered them to rats, and isolated the conversion products excreted in the urine and feces. The metabolites of pentachlorothiophenol and pentachlorothioanisol are excreted in both conjugated and free form. From extracts of the excreta, we isolated tetra- and trichlorobenzene with two or three sulphur-containing substituents on the ring, analogous compounds in which thiol groups were converted into sulphoxide and sulphone groups, as well as analogous compounds with a phenolic oxygen in addition to sulphur, and sulphur-containing compounds in which clorine was replaced by hydrogen. Following administration of the sulphoxide and of the sulphone of pentachlorothioanisol under analogous conditions, pentachlorothiophenol and pentachlorothioanisol and their metabolites were detected in the excreta of the animals. No evidence was obtained that the parent compounds are excreted in the unchanged form.

Animals↗
PubMed1979

[Documentation of arrhythmias - the value of long-term ECG monitoring].

Computer-supported long-term ECG-analysis, must be considered as complementary to other methods of documentation concerning arrhythmias. With the introduction of computers in the last several years, exact quantification and qualification of arrhythmias, over long monitoring periods, has become possible. With this method diverse forms of documentation and data presentation enhance its value of information and increase plausibility. Major indications for long-term ECG-monitoring of ambulatory patients are detection of occult arrhythmias, evaluation of subjective symptoms such as dizziness or syncope, recognition of pacemaker dysfunctions, selection of patients with coronary heart disease at high risk and evaluation as well as control of the efficacy of antiarrhythmic therapy.

Arrhythmias, Cardiac↗
PubMed1978

[Haemodynamic response to antihypertensive treatment with atenolol in patients with hypertension (author's transl].

The antihypertensive effect of atenolol, a cardioselective beta-blocker, was examined in 8 patients with essential hypertension. The most important haemodynamic changes observed were a significant reduction in heart rate (reduction in maximum heart rate at the end of symptom-limited exercise by 23% p less than 0.01) and a moderate fall in systolic blood pressure (reduction at submaximum level of exercise by 22%, p less than 0.01). The antihypertensive effect was attributable in half the patients to a drop in peripheral vascular resistance and in the other half evenly to a predominant reduction in cardiac output or to a reduction in both parameters. In view of the compensatory rise in stroke volume a significant reduction in cardiac output was not found. Symptom-limited exercise tolerance was increased in all patients. These results lead to the conclusion that the antihypertensive action of the cardioselective beta-blocker, atenolol is based on a lowering of the increased peripheral vascular resistance and a reduction in cardiac output; the latter mechanism is predominantly found in patients with hyperkinetic features.

Adolescent↗
PubMed1978

[Sudden cardiac death in patients with pacemakers].

The risk of sudden death in our material, is 13.6% of all deaths. 2. In 5 patients (1.6%) death was caused by failure of the pacemaker (PM), or the electrode. 3. Patients with an asynchronous PM have no higher risk for sudden death, than patients with demand PM. 4. In 9 of 44 patients, a dysfunction of the PM or electrode, can not be excluded. Thus, it must be strictly advised in all patients with an implanted PM, that an autopsy and control of the explanted PM and electrode should be performed. 5. Patients who have a higher risk for sudden death (total AV-Block, Adams-Stokes-Attacks) should be kept hospitalized at least 4 weeks after implantation, controlled more frequently than others, and should be labelled as high risk patients in their PM passport. 6. Control of the resistance in the patients circuit can detect impending failure of the electrode and prevent life threatening complications.

Death, Sudden↗
PubMed1978

[Circadian variations in the frequency of arrhythmia and quantitative analysis of rhythm disturbances].

In 29 patients with long term ECG monitoring the circadian rhythm of extrasystoles was investigated. A decrease of maximal frequency of extrasystoles was calculated for each hour and an increase of the minima during night was detected. In 77% of the patients also for 6 hour-segments a circadian rhythm could be calculated. The effect of the antiarrhythmic treatment on the frequency of extrasystoles was different depending on the frequency of the sinus rhythm.

Anti-Arrhythmia Agents↗
PubMed1977

Pre-excitation of the ventricle associated with total intra His bundle block.

A case with total intra-His bundle block and intermittent pre-excitation syndrome is presented. During A-V conduction there was a P-delta interval of 130 msec. with a P-A interval of 20 msec., an A-H interval of 60 msec. and an H-V interval of 50 msec. During rapid atrial pacing the P-delta interval increased primarily due to an A-H1 prolongation and a Mobitz type 2 block and total A-V block occured at increasing rates showing H1 following every A spike. The escape beats showed a normal width of the QRS complexes with preceding H2 spikes. After administration of Ajmaline the bypass tract was blocked and constant total A-V block occurred. It was concluded that there was a constant total intra-His bundle block and a nodoventricular or fasciculoventricular bypass tract with prolonged conduction to the ventricle. This bypass tract blocked sometimes spontaneously and could also be blocked by rapid atrial pacing and administration of drugs. The close anatomic proximity of the His bundle and Mahaim fibers is responsible for the simultaneous block resulting in total atrioventricular block.

Aged↗